Elue damper latch



Patented Oct. 6, 1953 UNITED STAT ES PTENT OFFICE 9 Claims,

The invention relates to; a latch for gravityopened flue dampers;

An object oithe invention is to provide a latch of the character described which is automatically controlled entirely by positioning movements of the damper with which it is associated.

Another object of the invention is to provide a flue damper latch which is applicable to damper plates of a usual flat form.

The invention possesses other objects and features of advantage, some of which,,with the foregoing, will be set forth. or be apparent in the following description of a typical embodiment thereof, and in the accompanying drawings, in

. which,

Figure I is a plan view showing the latch of my invention as" operatively' applied to the damper of an upright vent pipe of circular crosssection.

Figure 2 is a sectional view taken at the line 2'-2 in Figure 1.

Figure 3 is a. sectional view corresponding to that of Figure 2,.butv showing the damper in open position.

Figure 4 is a face view of the inoperativelydisposed' damper of. Figure 3; taken from the boltcarrying side thereof.

Figure 5 is an enlarged fragmentary perspective View showing the latch operativeas in Figures 1 and. 2'.

Figure. 6 is a face view of aflue-mounted latch late for cooperation with the latch bolt on the damper.

A. damper latch embodying my invention has been particularly shown as associated with aflue or vent pipe section 3' having aside wall 9 of circul'ar cross-section. The wall 9 mounts a usual circular damper plate it provided. with ahinge spindle 12 extending diametrically across it and through complementary bearing openings t3- provided in the wall, the. extremities otthe spindle l2 beyondthe wall 5 being shown as flattened for an operative retention. of the spindle with respect to the damper plate and flue Wall.

Essentially,. the latch of my invention. comprises a bolt member 14 hingedly mounted. at a central point-oi the damper plate 1. IV for swinging in a-fl-xed plane opposite to and spaced from the upper face of the. plate, and a. catch-plate it pro.- videcl by a member [6 mounted. onthe flue wall. 9

2, for cooperation with the bolt M to releasably support the damper plate I l in its operative position across the passage of the flue pipe by reason of the engagement of the free end of the bolt in a supporting notch provided by the catch-plate l5.

As particularly illustrated; the latch bolt- M is mounted on a member H having a fiat intermediate base portion l8 arranged for fixing to the damper H as by rivets t9 applied" through the members. The member I"! may be conveniently shaped from a strip of sheet material having p01- tions 2! and 22 correspondingly outstanding from an intermediate portion which comprises the base 8. The portion if of the member I l has a terminal part 2l-" extending parallel to the base part [8, and the part 2|" has one end of the bolt M hingedly attached thereto by a hinge pin 23:; the present bolt M is shown as shaped from a length of round rod having one end flattened and provided with an opening for loosely receiving the attaching hinge pin 23 through it. For a reason to'be hereinafter brought out, the bolt It has: angularly' related portions M" and I4" lying in a plane perpendicular to the axis of the hinge. pin 23.

The portion 22 of the bolt-carryingmember H is provided with a slot 24: extending across. it near its free end, and said slot constantly receives the bolt M for a confined movement along it while it is alternately engageable with the. upper and lower slot edges by reason of the looseness of its hinging connection at the pin 23. The present slot; 24 is symmetrically tapered, with its longitudinal center line in substantially parallel relation to the base It. at substantially the same distance from the base as the hinged end of the bolt [4. As particularly shown, the bolt I4 is hinged to the part 21" of the member I? at a point near one side thereof, and. the smaller end of. the. slot 24 is. at that. end which corresponds to the location of the bolt hinge 23. In mounting. the present bolt f4 on the damper, themember H is preferably so positioned on the damper that the bolt hinge pin 23 is at, or laterally opposite, the center point of. the damp'er mounting spindle [2,v while. a line from the smaller end of the slot, 24 to. the axis. of hinging of the bolt substantially perpendicular to the axis of hinging: of' the damper. whereby the bolt and its mounting member are carriedv on a damp'- er half bounded in part by the axis of the spindle i2. Noting that the latch bolt assembly has added an unbalanced weight to the damper half which mounts it, it will be understood that the freed damper will gravitationally assume the position shown for it in Figure 3, and that the bolt I l will then gravitationally engage the underlying slot end, particularly by reason of the fact that the bend in the bolt [4 extends parallel to the base it and toward a line between the bolt pivot and the other slot end; with the described arrangement, the uprightly disposed bolt 1 d is arranged to be gravitationally disposed and held against the smaller slot end as is shown in Fig ure 4.

It will now be seen that the catch-plate I5 has mutually spaced upper and lower portions [5' and i5" cooperative to provide between them a somewhat zig-zag path in an upright plane and in termediately providing a supporting notch 25 into which the portion of the bolt it beyond the slot 2 is laterally movable for securing the damper in its operative position and from which the bolt is removable for releasing the damper for its subsequent inoperative disposal by the action of gravity. The notch 25 is disposed at such a level that the bolt M resting therein disposes the damper in its passage-closing relation to the pipe 8 by intermediately engaging the upper edge of the slot 24 to support the underlying weighted half of the damper upon it, as is shown in Figures 1 and 5,

The catch-plate portions [5' and I5" are particularly shown as comprising mutually coplanar and laterally spaced upper and lower parts of the member [6, said member comprising a flat base portion 26 from which the catch-plate portions l5 and are su ported by flanges 2'! and 28 extending transversely from the base at opposite sides thereof. The catch-plate portion i5 extends above an intermediate point of the flange 2! and has a lower edge portion 29 extending obliquely upwardly from the flange to a downwardly directed portion 29' from which an edge portion 29" continues to the extreme side of the catch-plate portion !5 in generally parallel relation to the edge portion 29, the edge portions 29 and 28' cooperatively providing a downwardlyfacing notch 36. The catch-plate portion I5 extends from the flange 28 below the portion l5, and its upper edge 3| is provided with the upwardly-facing notch 25, the sides of this notch being defined by the top portion of the flange 28 and the upper edge 3! of the portion i5 extending upwardly from the flange 28 to a point 32 slightly beyond the notch of the catch-plate portion 15, from which point the lower edge 33 of the catch-plate portion extends obliquely in a convex arc to the bottom of the flange 28.

It will now be noted that the portion of the flange 2! below the edge 29 of the upper catchplate portion i5 is cooperative with the bottom edge 33 to define the adit end of the generally zig-zag path defined between the plate portions i5 and i5", and that the catch-plate assembly is mounted on the pipe side 9 in such a position that the free end of the damper-carried bolt M may be swung upwardly thereinto as the damper assumes a passage-closing position across the pipe 8; the member I6 is suitably fixed to the pipe wall 9 in appropriate position by rivets 28' engaging its base portion 26. A flexible pull cord 34 depends from a point of the damper plate 1 i which is at the opposite side of the spindle l2 from the bolt assembly, said'cord extending from an accessible point for its pulling, and being usable to effect a latching and unlatching of the operatively disposed damper in the manner hereinafter described.

When the damper is open, as in Figures 3 and 4, a downward pull on the cord as is arranged to rock the damper to and beyond its more-or-less horizontal operative position which is shown for it in Figures 1 and 2 and 5. As the free end of the bolt M, which is then engaged with the smaller end of the slot 24, moves upwardly in the adit defined between the flange 2? and the edge 33 to engage the lower edge portion 29 of the catchplate portion l5, it is then laterally engaged and moved by the catch-plate edge 29 into the notch 30 while the bolt is supported from the lower edge of the slot 24 to thereby limit the upward damper movement, and a subsequent release of the cord 34 permits a return swinging of the damper to effect a supported and guided movement of the bolt upon and along the edge 3! into the support notch 25 while the bolt engages the upper sides of the slot 24 for the support of the damper thereat. When the closed damper is to be opened, a pull on the cord 34 is arranged to swing the damper beyond its closed position to release the bolt for its supporting engagement with the upper edge of the slot 24 and to engage the bolt end against the under edge portion 29 of the upper latch plate portion E5 to laterally displace the bolt end beyond the flange 28 whereby a subsequent release of the cord permits a gravity swinging of the damper to its open position and a return of the bolt to its normally inoperative positioning at the smaller end of the slot 24.

In view of the foregoing, it will be understood that the disposal of the latch bolt id in the notch 25, and the removal of the latch bolt from said notch, are both eifected by successively swinging the damper slightly above its normal operative position by the use of the cord 34 to respectively engage the bolt with the guiding edge portions 29 and 29" of the catch-plate portion it" while it is supported from the damper on the lower edge of the slot 24. With reference to the positioning sliding of the bolt along the catch-plate edges 29 and 3! and 29", it will be noted that the slope of the bottom edge of the slot 24 facilitates the actions by reducing frictional resistance thereat. Also, since the present latching device lacks any springs in its combination, it is to be particularly noted that it is not subject to the usual operative deterioration of damper latches having spring controls; the present latch control is afforded solely by the cooperation of manual action through the cord 3% and by the action of gravity.

From the foregoing description taken in connection with the accompanying drawings, the advantages of the present flue damper latch will be readily understood by those skilled in the art to which the invention appertains. While I have described the principle of operation, together with a form of my invention which I now consider to comprise a preferred embodiment thereof, I desire to have it understood that the showings are primarily illustrative, and that such changes and developments may be made, when desired, as fall within the scope of the following claims I claim:

1. In combination with an upright fiue provided with a horizontally hinged damper plate releasably disposable in a predetermined closure plane across the flue, a latch bolt carried by the damper plate within the flue space for swinging adjustment thereon in a fixed path about an axis transverse to the axis of'hingi'ng of'the damper plate and between unlatched and latch'ed positions for the bolt withrespect to the damper plate, a catch-plate fixed within the fl'ue and providing areston which the free" endof the bolt is arranged to be" seated from above'for'supporting the damper plate in. its said. closure lane, and a guide means on the catch-plate provided with downwardly-facing guide faces above the cat'cliplate rest alternately engageable by said bolt end forresp'ect'ively thebolt from its unlatched and latched positions with respect to the dampen plate over and from over said rest by and upon. successive swingings of the. damper platebeyond its operative position from. its open and closed positions.

2. In combination with an upright flue provided with a horizontally pivoted damper comprising a plate which is disposed in the flue space and is arranged to gravitationally assume its open position and is releasably securable in a predetermined operative position across the flue space, a latch bolt carried by the damper plate within the flue space for swinging adjustment about an axis transverse to the axis of hinging of the damper, and between unlatched and latched positions for the bolt with respect to the damper plate, a member fixed within the flue and providing a rest on which the free end of the bolt is arranged to be disposed for supporting the damper in its operativ position, means actuatable to swing the damper from its open position to and beyond its operative position, a guide means mounted on the flue and providing a guide face above the rest provided by the member in the path of the unlatched bolt and engageable thereby to dispose the bolt above the rest by reason of an initial disposal of the damper beyond its operative position by the damper-swinging means for a gravitational damper-supporting seating of the bolt on the rest upon a return movement of the damper, and a guide means providing a guide face above the rest provided by the member in the path of the latched bolt and engageable thereby to dispose the bolt from over the rest to free the damper for its gravitational return to its open position by reason of a succeeding disposal of the damper beyond its operative position by the damper-swinging means.

3. A structure in accordance with claim 2 whereof the rest-providing member provides both said guide faces.

4. In combination with an upright flue provided with a pivoted plate comprising a damper which is disposed in the flue space and is arranged to gravitationally assume its open position and is releasably disposable in a predetermined operative position with respect to the flue, a latch bolt carried by the damper within the flue space for swinging in a fixed path opposite the damper and about an axis transverse to the axis of hinging of the damper and between unlatched and latched positions for the bolt with respect to the damper, a catch-plate fixed within the flue and providing a rest on which the free end of the bolt is arranged to be disposed for supporting the damper in its operative position when in latching position with respect to the damper, a pull member actuatable to swing the damper from its open position to and beyond its operative position, a first guide means fixed within the flue and providing a guide face above the catch plate rest which is engageable by said bolt by reason of the disposal of the disposal of the damper beyond its operative position to position the bolt above the rest for its seating v thereon when the damper-swingin pull member: re.- le'ase'cl, and. a second: guide means fixed within the flue and providing a guide face above: the catch plate restwhich engageablebysaid; bolt by reasorr of the disposal of: the damper beyond its-cperative position to dispose the seated bolt from over; said rest'to permit a gravity returnof the damper'to-its opempositionwhen the damperswinging pulF memb'eri's-releasedi 5. A structure: in: accordance with: claim 4 whereofthe guide face; faces downwardly and slopes upwardly from. a: point in thepath of upwardmovementof'the unlatched bolt to a stop positioning the engaged bolt abov'evthe. seat.

61 a structure: in accondance; with claim 4 whereof the second guide face faces downwardly and is inclined to the closure plane of the damper and extends above and from over the rest for cooperation with the bolt to dispose the bolt from over the rest and in unlatched position with respect to the damper when the damper-swinging means is actuated to swing the damper to engage the bolt with said face.

7. In a flue provided with a damper which is hingedly supported for swinging about a horizontal axis and is arranged to normally hang upright in inoperative position in the flue passage, a latch-bolt carried by the damper for swinging in a fixed path opposite the damper and about an axis transverse to the axis of hinging of the damper and between unlatched and latched positions of the bolt with respect to thedamper for its gravity disposal in a predetermined unlatched position with respect to the damper when the same is upright and for its frictional engagement with the damper when the same is swung from its upright position in a closing movement thereof, a catch member fixedly mounted on the flue and providing a rest arranged for engagement by the latch bolt to support the damper in its operative position, and a guide member mounted on the flue and providing first and second inclined guide faces above the catch member rest engageable by the bolt to respectively guide the latter into and out of disposal above the rest solely by reason of successive swinging movements of the damper beyond its operative position, the first said guide face extending across the path of movement of the bolt with the closing damper While the bolt is disposed in its unlatched position with respect to the damper.

8. In a flue provided with a damper which is hingedly supported for swinging between operative and inoperative positions thereof about a horizontal axis and is arranged to normally hang upright in the flue passage, a latch bolt carried by the damper for swinging in a fixed path opposite the damper and about an axis transverse to the axis of hinging of the damper and between unlatched positions at opposite sides of a latching position of the bolt with respect to the damper for its gravity disposal in one said unlatched position with respect to the damper when the same is swung from its upright position, a catch member fixedly mounted on the flue and providing an upwardly-facing seat arranged for damper-supporting engagement by the latch bolt, and a guide member fixedly mounted on the flue and providing downwardly-facing similarlyinclined first and second guide faces above the catch member seat cooperative with the positioned bolt to respectively guide the latter into and out of a position above th seat solely by reason of successive swinging movements of the damper beyond its operative position to engage the bolt with the respective guide faces, the first said guide face extending across the path of upward movement of the bolt in its said unlatched position with respect to the damper as the damper is swung to and beyond its operative position to engage the bolt with this guide face, and the second said guide face extending from over the bolt-receiving seat of the catch plate to dispose the bolt in its other unlatched position with respect to the damper while the bolt is engaged with this guide face.

9. A structure in accordance with claim 8 whereof the seat of the catch member comprises an upwardly-facing notch having a side sloping 8 to its bottom, and guide faces of the member are downwardly-facing and similarly inclined and are mutually offset to provide a stop face portion connecting them for disposing the engaged bolt abov said sloping side of the notch by the action of the first guide face.

WALTER C. SHVJPSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 846,542 Albertson Mar. 22, 1907 1,397,953 Gable Nov. 22, 1921 1,785,385 Lauer Dec. 16, 1930 

